Process for the production of film forming synthetic resins for hair fixatives

ABSTRACT

Process for the production of film forming synthetic resins for hair fixative compositions by reacting a methylolated 5,5-dialkylhydantoin containing 1-5 carbon atoms in each alkyl group at an elevated temperature in the presence of a bifunctional acid amide and/or amine. Hair fixative compositions containing 2-10% by weight of the resin product as the major or sole resin compound.

This is a division, of application Ser. No. 263,517, filed June 16,1972, now U.S. Pat. No. 3,987,010.

The use of solutions of film forming synthetic resins in hair fixativecompositions is known in the art. Liquid hair fixative compositions areused in the form of aqueous alcoholic solutions containing about 2-4%weight of lacquer raw materials or synthetic resins and minor amounts ofperfume oil or similar agents. Hair fixative compositions suitable forapplication as aerosols, the so-called hair sprays, usually containabout 3-6% weight of film forming synthetic resin, anhydrous alcohols,such as isopropanol and/or ethanol, halogenated hydrocarbons, such asdichloromethane, which serves as a latent solvent and/or 25-75% weightof a propellant such as carbon dioxide or the fluorochlorinatedhydrocarbons, e.g., the FREONS and auxiliary materials as perfume oils,plasticizers and the like.

Representative known film forming synthetic resins for hair fixativecompositions are the polyvinylpyrrolidone (PVP) and PVP/vinyl acetate(VA) copolymers, modified acrylics, quaternized acrylics,methylvinylether-maleic anhydride copolymers, VA-crotonic acidcopolymers, polyvinylimidazole, phthalic esters of pentaerythritol and5,5-dimethylhydantoin-formaldehyde resins. Synthetic resins based onpolyvinylimidazole and cellulose derivatives, although known to be usedfor hair fixative compositions, are generally less suitable for qualityreasons. A disadvantage of synthetic resins based on polyvinylpyrolidonefor hair fixative compositions is that they are hygroscopic and have anunpleasant odor. Moreover, these polymers and copolymers are relativelyexpensive. Also, it is known to be comparatively difficult to removethem from the hair by washing. Phthalic ester resins are disadvantageousbecause they tend to form scaly film on the hair which are hard to combout.

Attempts have been made to eliminate the drawbacks of each of the abovetypes of synthetic resins by mixing them with each other, which mayresult in a chemical interaction of the components, such astransesterification, etherification, and the like. For example, as shownin the German Published Patent Application No. 1,254,292, minor amountsof a synthetic resin consisting of 5,5-dimethylhydantoin (DMH) andformaldehyde have already been used along with other materials in suchmixtures. Synthetic resins of this type are known to be obtained byreacting DMH with an aqueous formaldehyde solution at elevatedtemperature in the presence of alkalis and optionally with an organicsolvent. However, these known commercial DMH/formalin condensates usedin hair fixative compositions have molecular weights lower than about500 and tend to be sticky. Moreover, they are hygroscopic and tend tohave a limited storage life. Accordingly, these low molecular weightcondensates have only been used in conjunction with other resincondensates and then only in minor amounts.

It is known from U.S. Pat. No. 2,155,863 that water soluble resins canbe prepared from 5,5 dialkyl hydantoins and formaldehyde and optionallyalso in the presence of urea or phenol, which serve to harden theresulting resins. A known disadvantage of the resinous products preparedwith urea is that as their melting point temperature range is increasedabove 100° C., the water solubility of the resulting resin products ismaterially reduced, that is, to a solubility substantially less than 50%even in hot water.

It is an object of the invention to produce a hair fixative compositionwhose synthetic resin component is an improved DMH/formalin condensate.Another object is to improve the known process for the production ofDMH/formalin condensates in such a way that the products obtained have arelatively high molecular weight and are completely or largely free fromthe above disadvantages. A still further object is the formulation of ahair fixative composition containing an improved DMH/formalin condensateas the major resin component or as the sole resin component.

According to the invention these objects are achieve by a process forthe production of film forming synthetic resin for hair fixativecompositions by reacting at an elevated temperature a methylolated5,5-dialkylhydantoin wherein each alkyl group contains from 1 to 5carbon atoms, preferably 1 to 2 carbon atoms per alkyl group, in thepresence of a lower aliphatic ketone and a bifunctional acid amideand/or an amine.

Further characteristics and advantages of the process according to theinvention will become evident from the following description.

It has now been found that by carrying out the self-condensationreaction of a methylolated 5,5-dialkylhydantoin at an elevatedtemperature in the presence of a lower aliphatic ketone and abifunctional acid amide and/or amine one is able to obtain a resinproduct of increased molecular weight in the order of from about 700 to3000 or more which is free from the objectionable stickiness of theprior art condensates or in which this objectionable property ismaterially decreased and which has a solubility in water sufficient forthe practice to permit it to be washed out of the hair in the usualmanner.

Suitable temperatures for the condensation reaction mixture can varyfrom about 70° up to about 115° C. and higher dependent on thetemperature of the reaction mixture at reflux.

In the condensation reaction one can use a lower alkanol or an aromatichydrocarbon as a solvent or reaction diluent and as an aid in theremoval of any water present. Representative solvents include methanol,ethanol, isopropanol, butanol and benzene.

In the process of the present invention it is desirable to carry out themethylolation of the 5,5-dialkylhydantoin with aqueous formaldehyde atan elevated temperature of from about 55° to about 100° C. and at a pHof from about 6 up to about 11. A particularly preferred procedure is tohave the bifunctional acid amide present during the methylolationreaction. The formaldehyde and the bifunctional acid amide reactants arepresent in the methylolation reaction in the mole ratios of 1.5 to 2.5moles, preferably 1.6 to 2.0 moles, of formaldehyde, and 0.2 to 2.5moles, preferably 0.3 to 2.0 moles, of the bifunctional acid amide, permole of the hydantoin.

It has been found that the molecular weights of methylolation productsof DMH can be considerably increased and the stickiness of the productsremoved by effecting the methylolation in the presence of urea and aminor amount of a lower aliphatic ketone; molecular weight and"hardness" of the products increase with growing urea content. Theensuing deterioration of the water solubility of the prior art resinproducts is overcome without substantial change in the softening rangesof the synthetic resins by using the urea together with specified minoramounts of a lower ketone, such as acetone or methyl ethyl ketone.Furthermore, the urea may be wholly or partly replaced by a diamine, inparticular ethylene diamine. The lower aliphatic ketone is used in anamount of from about 0.1 to 1.0 mole, preferably 0.2-0.3 mole per moleof urea. The amine is present in an amount of from 0.2 to 1 mole,preferably 0.3 to 0.5 mole, per mole of the hydantoin.

In the case of the amine additive it should preferably not be addeduntil the methylolation of the DMH is completed and most or all of thewater and/or any solvent are removed from the methylolated reactionproducts.

The use of the amine results in a further increase in the molecularweight of the products under the condensation reaction conditions. Thepreferred amines are ethylenediamine and propylenediamine. It has beenfound that this effect occurs also when using the higher molecularweight diamines, such as hexamethylenediamine, but the products producedwith higher diamines are low-melting or somewhat sticky and thereforeare less desirable.

By adding urea with the ketone and/or ethylenediamine, as reactants,according to the invention (urea having a quasi-hardening, the amine aquasi-plasticizing effect), it is now possible to effect thecondensation reaction of the known methylolated reaction products of DMHwith formaldehyde to form products having a solubility in watersufficient for the practice to permit them to be washed out of the hairin the usual manner and having a molecular weight of from about 700 toabout 3000 or more, and which products can be made either "harder" or"softer" as required. The products of the invention are suitable toserve as the major or the sole film forming component in hair fixativecompositions.

Following is a description by way of example of a method for carryingout the present invention.

COMPARATIVE EXAMPLE A

1.5 Moles dimethylhydantoin (192 g) are charged together with 0.5 moleurea (30 g) and 2.0 mole formaldehyde (200 g of 30% formalin) to areaction vessel typically used for condensation processes. The mixtureis adjusted to the required p_(H) value of 10 to 11 by adding 2N causticsoda solution. Thereafter the condensation reaction is conducted at 88°C. for 2 hours. The condensation is then continued under reducedpressure (15 mm H_(g)) and the reaction product concentrated by raisingthe temperature up to 135° C. After reaching this temperature thecondensation is continued at 135° C. and under reduced pressure of 15 mmH_(g) for 2 more hours. The solid resin obtained from the melt has amelting range of from 110° to 120° C. and only a poor water solubility.Even in hot water, far more than 50% of the resin remain undissolved.Consequently, this resin is unsuited for use in hair fixatives, as itcannot be completely removed by washing.

EXAMPLE 1

Comparative example A is repeated except that 0.1 mole acetone (5.8 g)is added. The resin thus obtained has a melting range of from 105° to120° C. and is soluble in water as required. This resin is an excellenthair fixative ingredient, since it is not sticky owing to its highmelting range and yet can be removed by washing.

EXAMPLE 2

115 Grams (0.9 mole) 5,5-dimethylhydantoin, 18 grams (0.3 mole) urea,3.5 grams (0.06 mole) acetone, and 150 grams (1.5 moles) 30% formalin,with the pH-value adjusted to 10-11 by means of NaOH, were reacted withagitation during 2 hours at 97°-98° C. The initial reaction product wasthen boiled down until solid, treated with 63 grams isopropanol and 1.2grams concentrated hydrochloric acid, and further reacted with agitationfor another 2 hours at 90° C. After neutralization with triethanolamine,the neutralized resin solution was concentrated under vacuum until themelting point of the resin product exceeded 90° C. The product obtainedhad a melting range of 96°-106° C.

EXAMPLE 3

384 Grams (3 moles) 5,5-dimethylhydantoin, 60 grams (1 mole) urea, 500grams (5 moles) 30% formalin, and 11.6 grams (0.2 mole) acetone werereacted with agitation at a pH-value of 10-11 and a temperature of 98°C. The solution was boiled down under vacuum until the residue had amelting point of 90°-95° C. The initial reaction product thus obtainedwas treated with 300 grams methanol and 5.5 grams concentratedhydrochloric acid and condensed for another 2 hours at 68°-72° C. Afterconcentrating the solution under vacuum, a resin product having amelting range of 105°-115° C. was obtained.

EXAMPLE 4

The initial reaction product from Example 3 was treated with 350 gramsn-butanol and 0.55 gram concentrated hydrochloric acid and furtherreacted for 3 hours at 113° C. After concentration under vacuum, a resinproduct having a melting range of 80°-90° C. was obtained.

EXAMPLE 5

256 Grams (2 moles) 5,5-dimethylhydantoin, 60 grams (1 mole) urea, 58grams (1 mole) acetone and 400 grams (4 moles) 30% formalin, with apH-value of 10-11, were reacted with agitation for 2 hours at 85° C. andthen concentrated under vacuum. A resin product having a melting rangeof 118°-130° C. was obtained.

EXAMPLE 6

256 Grams (2 moles) 5,5-dimethylhydantoin, 60 grams (1 mole) urea, 11.6grams (0.2 mole) acetone and 400 grams (4 moles) 30% formalin, with apH-value of 10-11, were reacted with agitation for 3 hours at 96° C. andthen concentrated to a highly viscous solution. The solution was treatedwith 200 grams methanol and 3.5 grams concentrated hydrochloric acid andfurther reacted for 3 hours at 73° C. After boiling down, a resinproduct having a melting range of 95°-115° C. was obtained.

EXAMPLE 7

80.6 Grams (0.63 mole) 5,5-dimethylhydantoin were methylolated with 107grams (1.07 moles) 30% formalin at 55° C. for 60 minutes, neutralizedwith triethanolamine and concentrated to a solids content of 95%. 100grams isopropanol and 15.2 grams (about 0.2 mole) 80% ethylenediaminewere added to the initial reaction product, and the resulting mixturewas further reacted with agitation for another hour at 84° C., and thendehydrated using isopropanol azetrope. A light yellow resin solution wasobtained which at 50% solids content had a viscosity of 1-2 minutes asmeasured in a 4 mm DIN cup at 20° C. The resin product began to melt at106° C.

EXAMPLE 8

76.8 Grams (0.6 mole) 5,5-dimethylhydantoin and 120 grams (1.2 moles)30% formalin were reacted with agitation for 60 minutes at 88° C.,neutralized with triethanolamine and concentrated to a solids content ofabout 95%. 200 ml. benzene and 23.8 grams (about 0.3 mole) 75%ethylenediamine were added and the resulting mixture was refluxed for 3hours with removal of 22 ml. of water. After removal of the benzene byvacuum distillation a solid resin was obtained which started to getsticky at 100°-110° C.

EXAMPLE 9

256 Grams (2 moles) 5,5-dimethylhydantoin and 68.5 grams (0.5 mole)salicylamide were methylolated with 500 grams (5 moles) 30% formalin ata pH-value of 6 for 4 hours at 95° C., concentrated under vacuum anddyhdrated with benzene. The solution was adjusted to a pH value of 2with hydrochloric acid and agitated for 5 hours at boiling temperatureuntil dehydration was completed. After neutralization withtriethanolamine and concentration, a faintly yellow resin product wasobtained having a melting range of 76°-88° C.

The synthetic resins according to the invention from Examples 1-6 haveosmometrically determined molecular weights of about 800-1200, and thosefrom Examples 7 and 8 have molecular weights of 1500-3000.

EXAMPLE 10

The synthetic resin from Example 7 which when dry started to soften at106° C., was used for preparing a solution containing 3.5% weight resin,about 66% weight anhydrous isopropanol and 30% weight dichloromethane.60 grams of this solution and 40 grams of a mixture of FREON 11/12(70:30) were filled into an aerosol spray can having a spin-effectnozzle. In the table below this solution is referred to as solution "A".

In a similar way another solution "B" was prepared using 1.8% weighteach of the dry product from Examples 2 and 7.

Another solution "C" was prepared by mixing the product from Example 7with a commercial vinylpyrrolidone/vinylacetatecopolymer (molar ratio70:30) in a weight ratio of 4:1 using the same solvent as for "A" and"B", so that a total resin content of 3.5% weight resulted.

The properties of solutions A-C according to the invention, particularlytheir effectiveness as sprayable hair fixatives, were compared withthose of commercial hair sprays. The solutions used for comparisoncontained the following film-forming agents:

Solution D: Phthalic ester

Solution E: Partially saponified polyvinyl acetate

Solution F: Vinylpyrrolidone/vinylacetate-copolymer (70:30)

Solution G: Dimethylhdantoin/CH₂ O condensate (molar ratio about 3:4;molecular weight about 480)

It should be noted that solution "G" was specially prepared forcomparison purposes and did not constitute a commercial product.Although the condensate contained in solution "G" is commerciallyavailable for use in hair sprays, it is only employed in conjunctionwith other synthetic resins.

Each of the solutions A-G contained about 3.5% weight synthetic resin.

The properties of the hair fixatives A-G compiled in the table belowwere rated according to the following scheme:

1 = very good

2 = good

3 = satisfactory

4 = unsatisfactory

                  TABLE                                                           ______________________________________                                               Hair Fixing                                                                             Facility of                                                                             Scaling of    Washa-                               Solution                                                                             Property  Combing   Resin Film                                                                            Fell  bility                               ______________________________________                                        A      2         2         none    2     2-3                                  B      2         2         none    2-3   2                                    C      1-2       2         none    2     2                                    D      3-4       3         none    3     2-3                                  E      2         2         none    2     2                                    F      2-3       2         none    2-3   2                                    G      3-4       2-3       heavy   2     2                                    ______________________________________                                    

As shown in the table, compositions A-C containing the resin product ofthe invention are equivalent, if not superior, to the commercial hairspray compositions D-F. Moreover, the compositions A-C are practicallycolorless, odorless, not irritating to the skin and are neutral or atleast non-corrosive. Where they show a weakly acid reaction, they canreadily be neutralized; where they react alkalinely, neutralization withacids will result only in a slight discoloration without impairment ofdesirable properties. The compositions A-C can be readily mixed witheach other without discoloration and therefore are suitable for mutualneutralization. The adjustment of a physiological pH-valve by mixing ofthe compositions is particularly advantageous. Furthermore, they arecompatible with the addition thereto of minor amounts of conventionalfilm forming resins, preferably such as vinylpyrrolidone/vinylacetatecopolymers or oilfree phthalates.

We claim:
 1. Process for the production of a water soluble, film-formingresin product having a molecular weight in the range of from about 700up to about 3000 or more for a hair fixative composition, whichcomprises reacting a 5,5-dialkylhydantoin wherein each alkyl groupthereof contains from 1 to 5 carbon atoms with aqueous formaldehydesolution in the mole ratio of from about 1.5 to about 2.5 moles offormaldehyde per mole of said hydantoin, at a temperature in the rangeof from about 55° up to about 100° C. and a pH in the range of fromabout 6 up to about 11 and recovering the resulting methylolated5,5-dialkylhydantoin from the resulting reaction products by removal offrom about 50 to 100% of water, then reacting at an elevated temperaturein the range of from 70° to about 115° C. said methylolated5,5-dialkylhydantoin in the presence of from about 0.2 to about 2.5moles of a mixture of urea and a diamine, per mole of said hydantoin. 2.Process as claimed in claim 1 wherein said dialkylhydantoin is amethylolated 5,5-dimethylhydantoin.
 3. Process as claimed in claim 1wherein said diamine is ethylene diamine.
 4. Process claimed in claim 1,wherein said urea is present in an amount of from about 0.3 to about 2moles per mole of said hydantoin.
 5. Process as claimed in claim 1wherein said diamine is present in an amount of from about 0.3 to about0.5 mole per mole of said hydantoin.
 6. Process as claimed in claim 1wherein condensation is carried out in a reaction diluent selected fromthe group consisting of a lower alkanol containing from 1 to 4 carbonatoms and benzene.
 7. Process as claimed in claim 6 wherein said loweralkanol is at least one member selected from the group consisting ofmethanol, isopropanol and butanol.
 8. Process as claimed in claim 1wherein the methylolation reaction is carried out in the presence of alower alkanol solvent.
 9. Process as claimed in claim 1 wherein themethylolation reaction is carried out in the presence of benzene as asolvent.
 10. Process as claimed in claim 8 wherein said solvent isremoved from the resulting reaction products.
 11. Process as claimed inclaim 9 wherein said solvent is removed from the resulting reactionproducts.
 12. Process for the production of a water soluble,film-forming hair fixative resin having a molecular weight in the rangeof from about 700 up to about 3,000 or more which comprises reacting5,5-dimethylhydantoin with aqueous formaldehyde solution in the moleratio of from about 1.5 up to about 2.5 moles of formaldehyde per moleof said hydantoin from about 0.2 to about 2.5 moles of a mixture of ureaand a diamine, per mole of said hydantoin at a temperature in the rangeof from about 55° up to about 100° C., and at a pH in the range of fromabout 6 up to about 11, and removing at least a major portion of waterfrom the resulting reaction product.
 13. Process as claimed in claim 12wherein following removal of said water, there is added to the resultingreaction product a lower alkanol and a minor amount of a mineral acid,and the resulting mixture is further reacted at a temperature of fromabout 68° to about 113° C., for from about 2 to about 3 hours, and theresulting further reacted product is concentrated under vacuum.